The present invention relates to an element analyzer.
There has been known a fuel-sulfur analyzer using a combustion-type UV-excitation method as one type of element analyzers. This type of fuel-sulfur analyzer comprises a combustion section for burning a sample.
In the combustion-type fuel-sulfur analyzer, a sample is injected into and burnt in the combustion section to gasify the sample, and the gasified sample is transferred to a detection section to determine a sulfur content of the sample.
The combustion-type fuel-sulfur analyzer generally includes a sample injection member for injecting a sample into the combustion section. When the sample injection member is composed of an auto-sampler including a syringe and a needle, a sample is first sucked in the syringe and the needle, and then the needle is moved toward the combustion section to discharge or inject the sucked sample into the combustion section.
However, when the sample is injected into the combustion section, a part of the injected sample can be attached onto a relatively low-temperature portion of the combustion section. The attached sample will be vaporized or gasified bit by bit in a subsequent measurement likely to cause an adverse affect on the resulting measured value.
On the other hand, in view of eliminating an adverse affect from a liquid sample used in a previous measurement, it has been contemplated to run a cleaning liquid through the needle and the syringe so as to clean the inner walls of the syringe and the needle. However, this method is still involved in a problem of the above adverse affect because it cannot clean the outer periphery of the needle on which some of the liquid sample has been attached during the previous measurement.
From this point of view, the combustion-type fuel-sulfur analyzer may be provided with a cleaning vessel to be filled with a cleaning liquid. In this case, the needle is immersed in the cleaning vessel to clean the outer periphery of the needle. However, this method has involved a cumbersome and time-consuming operation of manually replacing the liquid in the cleaning vessel at certain intervals. In addition, if the needle is desirably cleaned with a newly replaced cleaning liquid for each measurement, the operation of replacing the cleaning liquid should be carried out as a preparatory for each measurement.
In view of the above problems, it is therefore an object of the present invention to provide an element analyzer capable of facilitating a high-precision measurement without adverse affect from a sample used in a previous measurement.
In order to achieve the above object, according to a first aspect of the present invention, there is provided an element analyzer including a combustion section for burning a sample, a sample injection member for injecting the sample into the combustion section, and a detection section for measuring a gasified sample formed by burning the sample in the combustion section. Further, the element analyzer comprises a cleaning-agent injection member for injecting a cleaning agent into the combustion section.
The element analyzer according to the first aspect of the present invention can inject the cleaning agent from the cleaning-agent injection member into the combustion section and remove contaminations due to the sample attached on the combustion section so that a high-precision measurement can be performed without adverse affect from a sample used in a previous measurement.
According to a second aspect of the present invention, there is provided an element analyzer including a combustion section for burning a sample, a sample injection member for injecting the sample into the combustion section, and a detection section for measuring a gasified sample formed by burning the sample in the combustion section. Further, the element analyzer comprises a cleaning-agent injection member for injecting a cleaning agent into the combustion section in a more upstream position relative to a position where the sample is injected into the combustion section.
The element analyzer according to the second aspect of the present invention can inject the cleaning agent from the cleaning-agent injection member into the combustion section in a more upstream position relative to a position where the sample is injected into the combustion section. Thus, the sample attached on the combustion section can be more reliably removed.
In the above element analyzers, the sample injection member may serve as the cleaning-agent injection member. In this case or a case of using the sample injection member commonly as the cleaning-agent injection member, the measurement can be performed with a high degree of accuracy while removing contaminations, without adding any component serving as the cleaning-agent injection member.
Further, according to a third aspect of the present invention, there is provided an element analyzer including a combustion section for burning a sample, a sample injection member for injecting the sample into the combustion section, and a detection section for measuring a gasified sample formed by burning the sample in the combustion section. Further, the element analyzer comprises a cleaning vessel. The cleaning vessel includes a cleaning bath for receiving therein a cleaning liquid to be injected from the front end of the sample injection member inserted into the cleaning bath. The cleaning bath has a height allowing the outer periphery of the front end of the inserted sample injection member to be cleaned by the cleaning liquid injected into the cleaning bath. The cleaning vessel also includes a waste-liquid port for discharging the injected cleaning liquid of the cleaning bath at a flow volume less than that of the cleaning liquid to be injected from the sample injection member.
The element analyzer according to the second aspect of the present invention can fill the cleaning bath with the cleaning liquid up to a predetermined height, while a part of the cleaning liquid injected from the sample injection member is discharged from the waste-liquid port. Thus, the sample attached on the outer periphery of the front end of the sample injection member in a previous measurement can be effectively cleaned, and the outer periphery of the front end of the sample injection member can be cleaned with a cleanly refreshed cleaning liquid all the time.
Therefore, the sample attached on the outer periphery of the front end of the sample injection member during a process of sucking the sample in a previous measurement can be cleaned, thereby facilitating a high-precision element analysis without adverse affect from the sample used in the previous measurement.